Humoral Immunity

Question 1

T independent antigens do NOT
a. bind to BCR.
b. get presented on MHC Class II.
c. have repeating epitopes.
d. induce B cell proliferation.
e. provide co-stimulatory signals to B cells

Answer 1

b. get presented on MHC Class II.

Question 2

The humoral immune response to T-independent antigens includes production of
a. IgA.
b. IgM.
c. memory B cells.
d. memory T cells.
e. all of the above.

Answer 2

b. IgM.

Question 3

T-independent antigens are often
a. components of self cell membranes.
b. polyclonal B cell activators.
c. repeating peptide epitopes
d. too small to be phagocytosed and presented.
e. none of the above

Answer 3

b. polyclonal B cell activators.

Question 4

Before a B cell can receive T cell help, the B cell must
a. express membrane B7.
b. express membrane CD40L.
c. express membrane IFNg receptors.
d. go to the site of infection.
e. process and present peptide on Class II MHC.

Answer 4

e. process and present peptide on Class II MHC.

Question 5

Antigen-binding B cells entering the secondary lymphoid organs initially go to the
a. B cell areas where they can bind antigen presented by follicular dendritic cells.
b. B cell areas where they can process and present antigen to T cells.
c. plasma cell areas where they can secrete antibody.
d. T cell areas where they can be the predominant activator of naïve T cells.
e. T cell areas where they can find specific helper T cells.

Answer 5

e. T cell areas where they can find specific helper T cells.

Question 6

Germinal centers are
a. areas of lymphocyte generation in the bone marrow.
b. common in unimmunized mice.
c. sites of rapid antigen-induced B cell division in the lymph nodes and spleen.
d. surrounded by naïve T cells waiting to be activated.
e. None of the above is true

Answer 6

c. sites of rapid antigen-induced B cell division in the lymph nodes and spleen.

Question 7

In order for T cells to provide help to B cells, T cell and B cell epitopes must be
a. covalently linked.
b. identical.
c. non-identical.
d. peptides.
e. T-dependent.

Answer 7

a. covalently linked.

Question 8

B cell isotype switching is important for
a. increasing the avidity of the antibody.
b. providing antibodies of many different antigen specificities.
c. providing antibodies which can perform different effector functions.
d. signaling the B cells to become activated by follicular dendritic cells
e. signaling B cells to leave the lymph nodes and secrete antibody at the site of infection.

Answer 8

c. providing antibodies which can perform different effector functions.

Question 9

Affinity maturation of the humoral immune response is due to
a. continued stimulation of B cells by high levels of antigen on the FDC.
b. DNA recombination by products of the RAG genes.
c. isotype switching.
d. negative selection of T cells with the lowest helper potential.
e. positive selection of B cells with the highest affinity for antigen.

Answer 9

e. positive selection of B cells with the highest affinity for antigen.

Question 10

Isotype switching by B cells occurs in response to T cell
a. IFNg.
b. IL-4.
c. IL-5.
d. IL-6.
e. all of the above.

Answer 10

e. all of the above.

Question 11

Isotype switching resembles somatic recombination because both processes
a. are catalyzed by the products of RAG-1 and RAG-2.
b. are regulated by helper T cell cytokines.
c. can result in stop codons in coding sequences.
d. occur in developing B cells in the bone marrow.
e. result in the irreversible loss of DNA from the B cell.

Answer 11

e. result in the irreversible loss of DNA from the B cell.

Question 12

Somatic hypermutation results in
a. antibody with different CDR than the membrane Ig which originally bound antigen.
b. B cell apoptosis.
c. B cells with higher affinity for the stimulating antigen.
d. B cells which can no longer bind the stimulating antigen.
e. All of the above result from somatic hypermutation

Answer 12

e. All of the above result from somatic hypermutation

Question 13

Plasma cells
a. are all very long-lived.
b. divide and differentiate into memory B cells.
c. produce most of their antibody at the site of infection.
d. secrete antibodies as long as antigen binds their membrane Ig receptors.
e. None of the above are true.

Answer 13

e. None of the above are true.

Question 14

Which of the following is NOT a similarity between the cellular and humoral immune responses?
a. Antigen-specific lymphocytes undergo clonal selection and expansion.
b. Cytokine signals promote effector cell differentiation.
c. Memory cells are generated.
d. Macrophage cytotoxicity is increased.
e. Receptor isotype switching occurs.

Answer 14

e. Receptor isotype switching occurs.

Question 15

Humoral immunity involves all of the following EXCEPT
a. antibody-dependent cell-mediated cytotoxicity.
b. antibody secretion by plasma cells.
c. B cell activation by antigen plus cytokines.
d. immunoglobulin isotype switching.
e. macrophage activation by Th1 cells

Answer 15

e. macrophage activation by Th1 cells

Question 16

In the problem below dealing with linked T and B cell immune responses to haptens, the investigators chose to look at production of IgG rather than IgM because
a. IgG antibodies are easier to detect than IgM.
b. IgG is made before IgM in an immune response.
c. no IgM antibody can be produced to a hapten.
d. production of IgG requires T cell help but production of IgM does not.
e. None of the above is true.

Answer 16

d. production of IgG requires T cell help but production of IgM does not.

Question 17

In the practice problem below dealing with linked T and B cell immune responses to haptens, IgG is not produced in experiment #4 because
a. HEL is not an effective carrier for PC.
b. PC cannot be presented to B cells.
c. T and B cell epitopes need to be identical in order for the T cells to provide help.
d. T and B cell epitopes need to be physically linked in order for the T cell to provide help.
e. the same antigen epitopes were not given in both primary and secondary exposures.

Answer 17

d. T and B cell epitopes need to be physically linked in order for the T cell to provide help.

Question 18

Epithelial cells which secrete IgA to block pathogen entry are NOT found in the
a. digestive tract.
b. mammary glands.
c. respiratory tract.
d. salivary glands.
e. skin.

Answer 18

e. skin.

Question 19

Different Ig isotypes are found in different body locations because they
a. are secreted in different tissues.
b. bind to different FcR that allow them to cross tissue barriers.
c. have different addressins.
d. have different affinities for antigen.
e. None of the above is true.

Answer 19

b. bind to different FcR that allow them to cross tissue barriers.

Question 20

Neutralizing antibody provides effective immunity to
a. bacterial infection.
b. bacterial toxins.
c. virus infection.
d. Both a and b are correct.
e. All of the above can be blocked by neutralizing antibodies.

Answer 20

e. All of the above can be blocked by neutralizing antibodies.

Question 21

An inactivated toxin used in a vaccine is called a(n)
a. adjuvant.
b. attenuated vaccine.
c. hemagglutinin.
d. neutralizing antigen.
e. toxoid.

Answer 21

e. toxoid.

Question 22

FcgRI on binds with highest affinity to
a. antigen-bound IgG1 and IgG3.
b. complement-activated IgG1 and IgG3.
c. free IgE.
d. free IgG1 and IgG3.
e. None of the above.

Answer 22

a. antigen-bound IgG1 and IgG3.

Question 23

Binding of ligand to FcgRI on macrophages and neutrophils does NOT signal the cells to
a. acidify their phagocytic vesicles.
b. engulf antigen.
c. release their histamine-containing granules to initiate inflammation.
d. produce lactoferrin to compete with microbes for iron.
e. undergo oxidative burst.

Answer 23

c. release their histamine-containing granules to initiate inflammation.

Question 24

Successful immune responses to bacteria which resist phagocytosis because of a polysaccharide capsule depends on the production of
a. active complement anaphylatoxins.
b. armed effector CTL.
c. neutralizing antibodies.
d. opsonizing antibodies.
e. oxidative burst.

Answer 24

d. opsonizing antibodies.

Question 25

Successful immune responses to bacteria which adhere to mucosal surfaces in order to initiate infection depends on the production of
a. active complement.
b. armed effector CTL.
c. neutralizing antibodies.
d. opsonizing antibodies.
e. oxidative burst.

Answer 25

c. neutralizing antibodies.

Question 26

Successful immune responses to bacterial toxins depend on the production of
a. active complement.
b. armed effector CTL.
c. neutralizing antibodies.
d. opsonizing antibodies.
e. oxidative burst.

Answer 26

c. neutralizing antibodies.

Question 27

In order for NK cells to do ADCC, they must bind
a. antibodies to virus proteins expressed on infected cell membranes
b. B7.
c. CD16.
d. toxic oxygen radicals.
e. virus peptides expressed on infected cell membrane MHC.

Answer 27

a. antibodies to virus proteins expressed on infected cell membranes

Question 28

NK cells kill their targets in ADCC using
a. complement-mediated lysis.
b. Fas and FasL.
c. oxidative burst.
d. perforins and granzymes.
e. all of the above.

Answer 28

d. perforins and granzymes.

Question 29

Mast cells release their granule contents to stimulate inflammation in response to
a. antigen binding to IgE on mast cell FceR.
b. antigen binding to IgG on mast cell FcgR.
c. antigen binding to mast cell antigen receptors.
d. antigen binding to mast cell FceR.
e. IgE-coated antigen binding to mast cell FceR.

Answer 29

a. antigen binding to IgE on mast cell FceR.

Question 30

Successful immune responses to helminth parasites depends on the production of
a. active complement.
b. armed effector CTL.
c. neutralizing IgA.
d. opsonizing IgE.
e. opsonizing IgG.

Answer 30

d. opsonizing IgE.